JPS6025343Y2 - Water flow control device for resistance welding machine - Google Patents

Description

[Detailed description of the invention] This invention relates to a water flow system control device for resistance welding machines, and in particular, in view of the low usage rate of resistance welding machines, the current flow is stopped in the current flow control device regarding the flow of cooling water for resistance welding machines. This is a control device for a resistance welding machine that saves water by controlling a water stop device such as an electromagnetic valve so that the cooling water can be automatically stopped when the condition is reached.

Resistance welding machines generally have extremely low usage rates, and it is rare for the equipment to be used continuously, but the equipment generates a lot of heat while it is energized, and if the cooling water used for cooling is not passed through, the equipment may burn out. Because this is unavoidable, water is often forced to flow even when not in use to prevent water from flowing.In view of the current usage conditions described above, this design has been developed to prevent water flow from occurring immediately before the resistance welding machine starts energizing. To provide a control device capable of automatically shutting off water after starting water flow to a device, completing energization, and elapsed time for heat generated by the device to be removed by cooling water and after the temperature of the device falls below a set temperature. It is something.

Next, an embodiment of this invention will be explained with reference to a block diagram of the drawing, in which 1 is a power supply, 2 is a control for controlling the power supply to the resistance welding machine,
For example, the energization control element constituted by a control element such as a thyristor is in a conductive state and energized to the resistance welding machine transformer 3 during welding, and is in a non-conductive state and de-energized when not welding.

In the transformer 3 for a resistance welding machine, 3a and 3b are the power supply side, that is, the primary winding terminal 3c, and 3b are the load side, that is, the secondary winding terminal 3.
e and 3f are output contacts of a temperature detector provided at a heat generating location.

4 is a resistance welding device, 4a and 4b are terminals connected to the load side terminals 3c and 3d of the resistance welder transformer 3;
ct4d is the output contact of the temperature detector installed at the heat generating point; 4e and 4f are terminals of electromagnetic valves etc. that pressurize the electrodes to weld the workpiece; 4g and 4h are the terminals for the workpiece to be welded and welding started. This is the activation contact for activating the control.

5 is a control device for a resistance welding machine that combines the water-saving circuit of this invention; 5a and 5b are input terminals for its control power source; 5c is a terminal for giving an energization command to the energization control element 2; 5d, 5
e is a terminal that receives the temperature detected from the output contact of the temperature detector of the resistance welding machine transformer 3 and the resistance welding device 4; 5f, 5g;
is the operation output terminal of the pressurizing solenoid valve, etc., 5h, 5
i is an input terminal that receives a command to start welding control, and 5L5 is used to open a water-saving electromagnetic valve 7 immediately before energizing the resistance welding machine and predict the time required to cool down the resistance welding device 4 after energization ends. This is a terminal that outputs the voltage for operating the electromagnetic valve to close the circuit after a preset time has elapsed, and has a time dial that allows the output time to be set arbitrarily.

Furthermore, if the next energization control is performed within the set time, the water-saving circuit according to this invention is immediately reset and ready for the next timed operation.

Furthermore, 6 is a stop valve for a cooling water source for cooling the heat generated from the resistance welding machine transformer 3, the resistance welding device 4, etc., and 7 is operated upon receiving a command from the water saving circuit of the resistance welding machine control device 5. This is a water-saving electromagnetic valve. Cooling is performed from the outlet side of the valve 7 through a cooling water system path 8 via a heat generating source such as a welding device and a transformer for a welding machine, and 9 is a discharge point.

Also, the output contact 3 of the temperature detector of the transformer 3 and the resistance welding device 4
e, 3f, 4c, and 4d are contacts that are connected to terminals 5d and 5e of the resistance welding machine control device 5, and are output when the temperature rises above the set temperature due to heat generation during energization, and are used to set the water saving circuit. If the temperature remains higher than the set temperature even after the time has elapsed, it continues to be output until the temperature drops to the set value and serves to instruct the resistance welding machine control device 5 to open the water-saving electromagnetic valve 7.

The above is the configuration of the control device for a resistance welding machine with a water-saving circuit of this invention.

Next, the configuration of the control device for a resistance welding machine according to this invention will be explained in detail in a state of use.

First, during use, start contact 4gt of resistance welding device 4
When 4h is input manually or automatically, the resistance welding machine control device 5 starts its operation according to the following steps according to the initial pressurization time, energization time, and holding time, which are arbitrarily set in advance.

First, the electrode pressurizing valves 4e and 4f are activated to start pressurizing the workpiece.

This is the initial pressurized state.

Next, when the initial pressurization time has elapsed, an energization control command is issued from the terminal 5C in order to bring the energization control element 2 into a conductive state so that the workpiece to be welded is energized while in the pressurized state.

It goes without saying that this is the energized state, and that the energization control time is controlled for the set time.

After the energization time has elapsed, the control command from the terminal 5c to the energization control element 2 is cut off, and the energization control element 2 enters a non-conducting state, completing the energization of the workpiece.

The workpiece that has been energized continues to be pressurized for a holding time, and after a period of time, the resistance welding machine control device 5 releases the operation command to the electrode pressurizing valves 4e and 4f, and the workpiece is released. Ru.

The above is the welding cycle of the resistance welding device and is well known.

In the above-mentioned welding cycle, the water saving circuit of this invention has another water saving time circuit that can be set arbitrarily in the resistance welding machine control device 5. .

At the same time as the pressurization command is issued to 4f, an opening command is issued to the water-saving electromagnetic valve 7 provided in the cooling water source to prepare for energization according to the energization command issued from the resistance welding machine control device 5. The flow of cooling water to the transformer 3 and the energization control element 2 is started.

After energization is completed, the temperature of each heat generating part is gradually lowered by the cooling water, and by setting the time in advance for the temperature to drop to a temperature ready for the next energization, after the set time has elapsed, the resistance welding machine control device 5 will save water. A closing command is issued to the electromagnetic valve 7, and the flow of cooling water is stopped.

At this time, the water saving circuit of the resistance welding machine control device 5 is immediately reset when the next energization command is issued during the elapse of the water saving time to prepare for the next timed operation.

In addition, due to poor cooling water flow, high water temperature, abnormal heat generation in each device, etc., even after the preset water saving time of the water saving circuit has elapsed, the temperature detector 3e53L resistor attached to the resistance welding machine transformer 3 may If it is dangerous to stop the cooling water using temperature detectors 4c, 4d, etc. attached to the welding device 4, the set time of the water saving circuit is bypassed and the energization is prohibited.

As described above, this invention is a control device that allows the minimum amount of cooling water to flow through when using a resistance welding machine. Especially in resistance welding machines that are not used often, the amount of cooling water used is This can be significantly reduced compared to .

In addition, for cooling water circulation equipment used in large factories with a large number of resistance welding machines, etc., the cost of cooling water supply equipment (pumps, piping, filters, cooling devices), etc. can be significantly reduced. It can contribute to down.

[Brief explanation of the drawing]

The figure is a block diagram of one embodiment of this invention. 1 is a power source, 2 is a current control element, 3 is a transformer for a resistance welding machine, 4 is a resistance welding device, 5 is a control device for a resistance welding machine equipped with a water-saving circuit according to this invention, 6 is a cooling water source stop valve, 7 is a water-saving solenoid valve, 8 is a resistance welding equipment cooling water system path, and 9 is a cooling water discharge point.

Claims (1)

[Scope of utility model registration request] When passing cooling water through parts that generate heat such as the resistance welding machine transformer and resistance welding equipment while the resistance welding machine is in operation,
A temperature detector is provided in the part that generates heat, and the detection output is sent to a control device to compare a predetermined set temperature, and when the power is not turned on or the temperature is below the set temperature, the cooling water system is shut off via a water-saving electromagnetic valve. Also, the time from just before starting energization of the resistance welding device until the arbitrarily set water flow time elapses,
Also, a water flow system control device for a resistance welding machine, which operates the electromagnetic valve when the temperature exceeds the set temperature to start water flow through the cooling water system.